Mounting of electrode targets in storage tubes

ABSTRACT

Electrode target disks are mounted in storage tubes in spaced relation behind window panels within an annular centering groove in a metal frame signal ring and held in firm contact with bearing pressure by a retaining ring centered in the groove and held under bearing pressure by locking means which may take various forms, i.e., an expansible locking ring or locking lugs upset from the frame ring. The diameter of the groove, target disk and locking ring are differentially smaller than the inside diameter of the storage tube to permit easy access for ready replacement of the target disk through the inside of the tube.

United States Patent [1 1 Geyer 1 Apr. 8, 1975 1 MOUNTING OF ELECTRODETARGETS IN STORAGE TUBES [75] Inventor: Hans Geyer, Baldham, both ofGermany [73] Assignees: Paul Kahl, Munich; Siemens Aktiengesellschat't,Berlin & Munich, Germany [22] Filed: Apr. 23, 1973 [2]] Appl. N0.:353,750

Related US. Application Data [63] Continuation-impart of Ser. No.157,096, June 28,

[30] Foreign Application Priority Data [51] Int. Cl. H0lj 29/02; HOlj29/45; HOlj 29/82 [58] Field of Search. 313/65 R, 65 A, 65 T, 65 AB,313/66, 285, 292, 67, 68 R, 68 D [56] References Cited UNITED STATESPATENTS 2,917,574 12/1959 Toulon 313/65 R X 3.030536 4/1962 Hackett etal. 313/85 R 3,073,981 1/1963 Miller et a1. 313/390 3,271,608 9/1966Rome et a1. 313/388 3,303,373 2/1967 Alting-Mees 313/65 R 3,325,6726/1967 Funahashi et al..... 313/65 A X 3,437,860 4/1969 Ney 313/65 T3,704,387 11/1972 Carpenter et a1. 313/67 3,725,711 4/1973 Sadler r313/66 Primary E.raminer-Robert Segal Attorney, Agent, or Firml-lill,Gross, Simpson, Van Santen, Steadman, Chiara & Simpson [57] ABSTRACTElectrode target disks are mounted in storage tubes in spaced relationbehind window panels within an annular centering groove in a metal framesignal ring and held in firm contact with bearing pressure by aretaining ring centered in the groove and held under bearing pressure bylocking means which may take various forms, i.e., an expansible lockingring or locking lugs upset from the frame ring. The diameter of thegroove, target disk and locking ring are differentially smaller than theinside diameter of the storage tube to permit easy access for readyreplacement of the target disk through the inside of the tube.

15 Claims, 2 Drawing Figures 5a 5 3 I I I MOUNTING OF ELECTRODE TARGETSllN STORAGE TUBES The present application is a continuation in-part ofour pending application Ser. No. 157,096 filed June 28,,

1971 with respect to which priority claim was established in regard toGerman Patent Application No. P 37 981 filed July 30, 1970.

This invention relates to mounting of storage elec' trode target disksin picture-recording or electric signal-storage tubes, and is moreparticularly concerned with mounting of such target disks separate andspaced from glass front window panels or plates on the tubes.

Heretofore, a photo-sensitive layer has commonly been vapor deposited onan electrically conductive glass plate. However, where thephoto-sensitive layer is in the form of a semi-conductor storageelectrode target on which, for example, 600,000 photo diodes/cm areapplied according to the integrated circuit technique, a differentarrangement must be used. Such targets are employed in video cameratubes and may also be employed in electric signal storer and/orintermediate storer tubes. Prior attempts to solve the mounting of suchtargets have not been satisfactory due to high cost caused in productionby, among other things, re quirement for several working cycles. Forexample, in prior arrangements it has been impossible to remove orexchange the electrode target where that becomes desirable for anyreason as where testing shows the target to be defective, withoutopening and reworking the window end of the tube.

An important object of the present invention is to overcome theforegoing and other disadvantages, deficiencies, inefficiencies,shortcomings, and problems in prior methods and structures, and toattain important advantages and improvements as will hereinafter becomeapparent.

Another object of the invention is to provide a simple and efficientimproved, new apparatus for mounting electrode targets in tubes of thecharacter indicated.

A further object of the invention is to mount elec trode targets readilyreplaceably in tubes of the character indicated.

Still another object of the invention is to provide a low cost,efficient, rugged, simple mounting of electrode target disks in storagetubes.

Yet another object of the invention is to provide an arrangement suchthat a standard form of tube can be equipped with either aphoto-sensitive or a storagesensitive target.

Other objects, features and advantages of the invention will be readilyapparent from the following description of certain preferred embodimentsthereof, taken in conjunction with the accompanying drawing, althoughvariations and modifications may be effected without departing from thespirit and scope of the novel concepts embodied in the disclosure, andin which:

FIG. 1 is a fragmentary longitudinal sectional view through the forwardend portion of a tube such as a video recording tube embodying featuresof the invention; and

FIG. 2 is an enlarged fragmentary vertical sectional view similar toFIG. 1 but showing a modification.

Having reference to FIG. 1, a calibrated glass tube 1 is provided at itsforward end with a flared, generally conical end portion 2 across whichis mounted a glass window plate or panel 3 carried by a metal frame ring4 which functions as a signal ring. As will be observed, the outsidediameter of the ring 4 is greater than the maximum diameter of theflared enlargement 2 so that the ring perimeter is freely accessible.

A hermetically sealed relation of the tube 1 and window 3 to the ring 4is attained by simultaneously bonding the glass members to the metalring 4, which is of a compatible coefficient of expansion, as by meansof high frequency heating. In preparation for such bonding, the terminusof the flared tube portion 2 is uniformly ground flat to receive theframe ring 4 flat thereagainst. Of course the window panel 3 beingdesirably flat will fit marginally close against the outer face of thering 4. In the example shown, the diameter of the window panel 3 issmaller than the outside diameter of the ring 4. By thus assembling andbonding the glass members 1 and 3 to the metal ring 4, the assembly canbe heated without difficulty for several hours to, for example, 450Cwhich is especially advantageous during production. For its principalfunction of mounting a storage electrode target disk 6, the frame ring 4is of an inside diameter to extend a limited distance inwardly relativeto the inside diameter of the tube 1.

According to the present invention new and improved means are providedfor mounting the target disk 6 on the axially inner side of the ring 4in a manner to enable free mounting and exchange of the disk 6 throughthe inside of the tube 1. To this end the ring 4 is provided with anannular centering, rabbet groove 5 in the axially inner side of itsradially inner margin, within which a margin of the scanning target disk6 (shown schematically) is engaged and clamped by means of a clampingring 7 held in place by an expansible and contractile retaining splitspring ring 8. To accommodate this relationship, it will be observedthat the clamping ring 7 is of a thickness slightly greater than thedepth of the groove 5, and the outside diameter of the ring 7 issufficiently less than the progressively flaring diameter of the innersurface of the tube portion 2 to accommodate the expanded locking ring 8on a diameter which enables the locking ring to thrust against theadjacent outside margin of the clamping ring with sufficient but notexcessive pressure so as to effect firm electrical contact but to avoidcrushing the clamped margin of the target disk 6 which may comprise athin glass wafer or any other suitable and possibly relatively fragilematerial.

Locking thrust force is generated in the ring 8 by the combined actionof its expansibility acting to return with substantial uniformity to aslightly larger normal diameter than the diameter to which it is held inthe locking relationship by a cam surface and thrust shoulder 2aprovided by the inside flaring surface of the tube head end portion 2.An advantage of the firm but not excessive clamping pressure applied bythe locking ring 8 against the clamping ring 7 resides in that assuranceis afforded of good contact between the margin of the target member 6and the metal frame ring 4 through which video signals are transmitted.As will be observed, the length of the cam surface 2a is sufficientradially and axially inwardly relative to the line on which the lockingring 8 shoulders thereagainst, to extend radially inwardly to juncturewith an inner cylindrical surface la of the wall of the tube 1 on adiameter on the order of half of the cross sectional diameter of thelocking ring. This assures thorough locking retention of ring 8 in itsoperative locking position against the cam surface 2a serving as athrust shoulder and the clamping ring 7, while minimizing the amount ofexpansion and contraction range required in the locking ring 8 to enablemanipulation of the same into and, out of the locking position.

As will be observed in FIG. 1, the outside diameter of the target disk 6and the clamping ring 7 as well as the diameter of the groove 5 whichholds these elements centered is less than the diameter of the tubeinsidewall surface axially inwardly from the flared tube head endenlargement tube. An important advantage of this arrangement is that thetarget 6 can not only be preformed and then inserted and mounted withthe rings 7 and 8 in place on the ring 4 through and from within thetube 1 after the head end of the tube assembly has been completed, butthe target 6 can also be exchanged at any time together with theindividual components 7 and 8 of the mounting structure if replacementis required after quality tests, through the inside of the tube 1without necessitating discarding of the entire tube assembly or openingand reworking the window or head end of the tube. It may also be notedthat while the target mounting assembly affords numerous advantages in aphysical sense as will be evident and as already pointed out, such asease of assembly, centered retention of parts, and ready replaceability,quite adequate effective target area is freely exposed within the insideperimeter diameter of the rings 4 and 7, consistent with the tubeenvelope diameter.

Interference with operational access to the exposed scanning target areais avoided by having the locking ring 8 so related to the clamping ring7 as to be well spaced at the inside perimeter of the ring 8 from theinside perimeter of the clamping ring 7, as shown. Further, thethickness of the inner target-carrying margin of the frame ring 4 is ata minimum consistent with structural stress resistance requirements sothat access to the marginal portion of the target area is as free aspossible under the circumstances. To this end, for example, the axiallyouter side of the radially inner margin of the frame ring 4 is desirablyprovided with an annular groove 50 in its outer face, opposite to thegroove 5 whereby not only is such inner margin of the frame ring reducedin thickness, but an offset spaced relation is provided from the windowpanel 3 affording a wider angle of access for incoming image to thetarget 6. In addition, the offsetting groove 5a provides a convenientdiametrical enlargement of the clearance space between the window 3 andthe target 6 for communication of one or more bypass passages 9 throughthe ring 4 between the clearance space and the interior of the tube 1into the annular enlargement groove adjacent to the extremity of thegenerally conical widening 2 of the tube head portion. Thereby when thetube 1 is interiorly evacuated as is necessary for proper functioning ofthis type of tube, the clearance area between the window 3 and thetarget 6 is likewise evacuated. The passages 9 may be slots or borings,as preferred.

In FIG. 2 another desirable arrangement is disclosed for attaining thesame results as in the form of FIG. 1. To this end, the glass tube 1'having a generally cylindrical inner diameter surface In and a generallyflaring end portion 2' on its head end carries a window disk 3 throughthe medium of the metal signal frame ring 4 all secured together as apre-assembly in the manner already described. In this form of theinvention, also, the frame ring 4 has an inside diameter greater thanthe diameter of the inside wall surface la of the tube and is providedwith a rabbet groove 5' on the axially inner side of the radially innermargin of the ring 4 within which the margin of the storage electrodedisk member 6 is secured in electrically sound engagement with the ring4 within the groove 5 by means of the clamping ring 7', the outsidediameter of the groove 5', of the disk 6, and the ring 7' beingsufficiently smaller than the diameter of the tube inside wall la toenable mounting of the target disk 6' and the ring 7' within the groove5' through and from within the tube 1' after the head structure of thetube 1' including the window 3' and the ring 4 has been completed as asub-assembly. It will also be noted that the offsetting groove 5a hasone or more bypass passages 9 communicating through the ring 4' with theinside of the tube 1 past the groove 5 and the clamped target diskmargin for the same purpose and to the same effect as described for thecorresponding groove 5a and bypass passage 9 in FIG. 1.

Means are provided for releasably securing the ring 7 in clampingrelation to the margin of the disk 6', but in this instance comprisingutilizing material of the ring 4 itself for the purpose. To this end, aradially and axially inner edge 10 of the metal frame ring 4' hasmalleably upset from a plurality such as three or four equidistantlyspaced limited areas therein respective retaining or locking tabs 12which extend generally radially inwardly and are bent toward and intoengagement with the axially inner side of the ring 7 to thrust it towardthe margin of the target disk 6'. To facilitate this, the depth of thegroove 5 is at least slightly greater than the combined thickness of thetarget disk 6 and the clamping ring 7. In addition, resilient, springpressure is advantageously provided for between the clamping disk 7' andthe margin of the disks 6 not only to assure increased electricalcontact pressure of the target disk 6 against the ring 4, but also toabsorb or damp pressure or force generated during formation of thelocking tabs 12. Advantageously, an annular transversely concave convexrelief spring ring 13 of the same diameter as the ring 7' is providedfor this purpose having its convex face in engagement with the margin ofthe disk 6 under compression of the clamping ring 7 thrustingthereagainst and held under such compressing thrust by the locking tabs12. By reason of its resilient flexibility, the spring 13 compensatesrelief or temperature differentials so that there is never any loosenessin the electrical contact of the target disk with the ring 4', and inaddition shocks or vibrations are readily absorbed thereby protectingthe target disks 6'.

Should it become necessary after the assembly has been completedincluding locking the clamping ring 7 by means of the tabs 12, to removethe target disk 6' as for replacing the same, that can be readily doneby bending the tabs 12 out of the way, or even removing the samealtogether since they are of relatively small mass of the malleablematerial of the ring 4'. Thereby the clamping ring 7 and the spring ring13 as well as the disk 6 can be easily removed through the interior ofthe tube 1. After the disk 6 or a replacement therefore has beeninserted through the tube 1 into the groove 5, the spring ring 13 andthe clamping ring 7' are replaced, and the same locking tabs 12, or newlocking tabs 12 are bent into thrusting locking engagement with theclamping ring 7.

Among thenumerous advantages of the present invention, it may againbeemphasized that the particular target mounting disclosed enables thesame basic discharge tube structure to be employed both forphotosensitive and for storage-sensitive targets. Thus the schematicallyillustrated target 6, 6 may be equipped for either of these purposes, asdesired, while the remaining components of the assembly, asstandardized, remain the same.

It will be understood that variations and modifications may be effectedwithout departing from the spirit and scope of the novel concepts ofthis invention.

We claim as our invention:

1. Mounting of a target disk on the end of a tube of the characterdescribed which includes a window panel across said end, both said tubeand said window pane] being formed from glass, comprising:

said tube end being on a flared head portion of the tube;

said end being a planar receiving surface on the flared head;

a metal frame ring of at least as large diameter as said end having anaxially inner side bonded to said planar surface;

said glass window panel having a margin engaging the axially outer sideof said frame ring and bonded thereto;

said frame ring having on its axially inner side a radially inner marginfacing axially inwardly relative to the tube;

the target disk having a margin engaging said frame ring margin;

a clamping ring engaging against the axially inner side of said targetdisk margin;

a locking ring engaging said tube head and said clamping ring andthrusting the clamping ring into clamping relation to the disk margin;

said disk and said clamping ring being of smaller outside diameter thanthe inside diameter of said tube; and

said locking ring comprising a split expansile spring ring which isexpansible to larger diameter than the inside diameter of the tube so asto effect engagement with said flared head, but which is of smallerinside diameter than the inside diameter of the tube so as to engage inthrusting relation with said clamping ring.

2. A target disk mounting according to claim 1, said frame ringsubstantially spacing said window panel and said target disk apart, anda bypass passage through said frame ring communicating with the spacebetween the panel and the disk and with the interior of the tube.

3. A target disk mounting according to claim 1, wherein said margin ofthe clamping ring has a groove within which the margin of the targetdisk is engaged and within which said clamping ring fits, said clampingring being of a greater thickness than the depth of the groove so as toproject axially inwardly relative to said axially inner side of theframe ring and to facilitate the engagement of the locking ring with theclamping ring. V

4. Mounting of a target disk in a storage tube having permanentlysecured to an end thereof a metal signal frame ring of at least as largeoutside diameter as said tube and with a window panel permanentlymounted on said ring in closing relation to the tube end, comprising:

said frame ring being of substantially smaller inside diameter than aninside wall of said tube;

an annular rabbet type groove in a radially inner margin of a face whichfaces axially inwardly away from said window panel on said frame ring;

a target disk having a margin releasably engaged in said groove;

a clamping ring received in said groove and clamping said target diskmargin against the frame ring within the groove;

said clamping ring having its outside diameter and said disk having itsdiameter smaller than the diameter of said inside wall of the tube sothat both the disk and the clamping ring can be assembled through thetube within said inside wall and into mounted position within saidgroove;

said inside wall of the tube having a flare at said end and therebyproviding a groove between said frame ring and said flare; and

an expansible ring member engaging said flare and releasably engagingthe clamping ring at its axially inner side and locking the clampingring in place, said ring member being adapted to be manipulated into andout of the locking engagement with the clamping ring, within the tube.

5. A mounting according to claim 4, including passage means in saidframe ring bypassing the margin of said target disk and the clampingring for equalizing the atmosphere between said window pane] and saidtarget disk and the interior of the tube axially inwardly from thetarget disk,

6. A mounting according to claim 5, wherein said frame ring has on itsaxially outer side a groove communicating with the area between thewindow panel and the target disk, and said passage means communicateswith said groove.

7. A mounting according to claim 4, wherein said expansible ring memberis in the form of a resilient split locking ring.

8. A mounting according to claim 4, wherein said expansible ring membercomprises a split spring locking ring which is retractable to asubstantially smaller diameter than said inside wall facilitatingmovement thereof into and out of the locking relation to the clampingring and is expansible to larger diameter than the inside wall so as toeffect engagement with said flare and is then of smaller inside diameterthan the inside diameter of the clamping ring but of larger insidediameter than the outside diameter of the clamping ring so as to assureengagement with the clamping ring when the expansible ring member isexpanded into engagement with said flare.

9. Mounting of a target disk in a storage tube having permanentlysecured to an end thereof a metal signal frame ring of at least as largeoutside diameter as said tube and with a window panel permanentlymounted on said ring in closing relation to the tube end, comprising:

said frame ring being of substantially smaller inside diameter than aninside wall of said tube;

an annular rabbet type groove in a radially inner margin of a face whichfaces axially inwardly away from said window panel on said frame ring;

a target disk having a margin releasably engaged in said groove;

a clamping ring received in said groove and clamping said target diskmargin against the frame ring within the groove;

said clamping ring having its outside diameter and said disk having itsdiameter smaller than the diameter of said inside wall of the tube sothat both the disk and the clamping ring can be assembled through thetube within said inside wall and into mounted position within saidgroove; and

locking means comprising locking tabs carried by said frame ring andextending into locking engage ment with said clamping ring.

10. A mounting according to claim 9, including passage means in saidframe ring bypassing the margin of said target disk and the clampingring for equalizing the atmosphere between said window panel and saidtarget disk and the interior of the tube axially inwardly from thetarget disk.

11. A mounting according to claim 9, wherein said groove is deeper thanthe combined thickness of said disk and clamping ring, and said tabs areformed from material of said mounting ring malleably upset therefrominto said locking engagement with the clamping ring.

12. A mounting according to claim 9, wherein said clamping ringcomprises a rigid ring member, and a resilient pressure spring ringdisposed between said rigid ring member and the margin of said disk andcompressed by the rigid ring member toward and into engagement with thedisk margin.

13. A mounting according to claim 12, said pressure ring comprising aconcave convex cross section resilient metal ring having a convex faceengaging the disk margin.

14. Mounting of a target disk within the end of a storage tube whichincludes a window panel across said end and a metal signal frame ringpermanently secured between said window and said tube end and having aninside diameter which is smaller than an inside wall diameter of thetube, comprising:

a target disk;

said frame ring having a groove inset in its radially inner axiallyinwardly facing margin within which the margin of said disk is seated;

compressible means thrusting against said disk margin;

a clamping ring fitting in said groove and pressing against saidcompressible means; and

means comprising locking tabs carried by said frame ring and thrustingsaid clamping ring toward said disk margin in said groove to maintainthe compressible means under compression against the disk margin.

15. A mounting according to claim 14, wherein said resilientcompressible means comprise a concave convex spring ring having a convexface in engagement with said disk margin.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3, 76,897 DATED April 8, 1975 INVENTOR(S) Geyer It is certified that errorappears in the ab0ve-identified patent and that said Letters Patent arehereby corrected as shown below:

On the front page of the patent, column 1, [75], should read:

Column 1, [73] should read:

"[7 Assignee: Siemens Aktiengesellschaft of Berlin 81 Munich, Germany--Signed and gealed'this eleventh 0f N0vemberl975 [SEAL] Arrest:

RUTH C. MASON C. MA-RSHALL DANN .-1t!es1ing Officer Commissioner (ifIalenrs um! Trudcmurkx

1. Mounting of a target disk on the end of a tube of the characterdescribed which includes a window panel across said end, both said tubeand said window panel being formed from glass, comprising: said tube endbeing on a flared head portion of the tube; said end being a planarreceiving surface on the flared head; a metal frame ring of at least aslarge diameter as said end having an axially inner side bonded to saidplanar surface; said glass window panel having a margin engaging theaxially outer side of said frame ring and bonded thereto; said framering having on its axially inner side a radially inner margin facingaxially inwardly relative to the tube; the target disk having a marginengaging said frame ring margin; a clamping ring engaging against theaxially inner side of said target disk margin; a locking ring engagingsaid tube head and said clamping ring and thrusting the clamping ringinto clamping relation to the disk margin; said disk and said clampingring being of smaller outside diameter than the inside diameter of saidtube; and said locking ring comprising a split expansile spring ringwhich is expansible to larger diameter than the inside diameter of thetube so as to effect engagement with said flared head, but which is ofsmaller inside diameter than the inside diameter of the tube so as toengage in thrusting relation with said clamping ring.
 2. A target diskmounting according to claim 1, said frame ring substantially spacingsaid window panel and said target disk apart, and a bypass passagethrough said frame ring communicating with the space between the paneland the disk and with the interior of the tube.
 3. A target diskmounting according to claim 1, wherein said margin of the clamping ringhas a groove within which the margin of the target disk is engaged andwithin which said clamping ring fits, said clamping ring being of agreater thickness than the depth of the groove so as to project axiallyinwardly relative to said axially inner side of the frame ring and tofacilitate the engagement of the locking ring with the clamping ring. 4.Mounting of a target disk in a storage tube having permanently securedto an end thereof a metal signal frame ring of at least as large outsidediameter as said tube and with a window panel permanently mounted onsaid ring in closing relation to the tube end, comprising: said framering being of substantially smaller inside diameter than an inside wallof said tube; an annular rabbet type groove in a radially inner marginof a face which faces axially inwardly away from said window panel onsaid frame ring; a target disk having a margin releasably engaged insaid groove; a clamping ring received in said groove and clamping saidtarget disk margin against the frame ring within the groove; saidclamping ring having its outside diameter and said disk having itsdiameter smaller than the diameter of said inside wall of the tube sothat both the disk and the clamping ring can be assembled through thetube within said inside wall and into mounted position within saidgroove; said inside wall of the tube having a flare at said end andthereby providing a groove between said frame ring and said flare; andan expansible ring member engaging said flare and releasably engagingthe clamping ring at its axially inner side and locking the clampingring in place, said ring member being adapted to be manipulated into andout of the locking engagement with the clamping ring, within the tube.5. A mounting according to claim 4, including passage means in saidframe ring bypassing the margin of said target disk and the clampingring for equalizing the atmosphere between said window panel and saidtarget disk and the interior of the tube axially inwardly from thetarget disk.
 6. A mounting according to claim 5, wherein said frame ringhas on its axially outer side a groove communicating with the areabetween the window panel and the target disk, and said passage meanscommunicates with said groove.
 7. A mounting according to claim 4,wherein said expansible ring member is in the form of a resilient splitlocking ring.
 8. A mounting according to claim 4, wherein saidexpansible ring member comprises a split spring locking ring which isretractable to a substantially smaller diameter than said inside wallfacilitating movement thereof into and out of the locking relation tothe clamping ring and is expansible to larger diameter than the insidewall so as to effect engagement with said flare and is then of smallerinside diameter than the inside diameter of the clamping ring but oflarger inside diameter than the outside diameter of the clamping ring soas to assure engagement with the clamping ring when the expansible ringmember is expanded into engagement with said flare.
 9. Mounting of atarget disk in a storage tube having permanently secured to an endthereof a metal signal frame ring of at least as large outside diameteras said tube and with a window panel permanently mounted on said ring inclosing relation to the tube end, comprising: said frame ring being ofsubstantially smaller inside diameter than an inside wall of said tube;an annular rabbet type groove in a radially inner margin of a face whichfaces axially inwardly away from said window panel on said frame ring; atarget disk having a margin releasably engaged in said groove; aclamping ring received in said groove and clamping said target diskmargin against the frame ring within the groove; said clamping ringhaving its outside diameter and said disk having its diameter smallerthan the diameter of said inside wall of the tube so that both the diskand the clamping ring can be assembled through the tube within saidinside wall and into mounted position within said groove; and lockingmeans comprising locking tabs carried by said frame ring and extendinginto locking engagement with said clamping ring.
 10. A mountingaccording to claim 9, including passage means in said frame ringbypassing the margin of said target disk and the clamping ring forequalizing the atmosphere between said window panel and said target diskand the interior of the tube axially inwardly from the target disk. 11.A mounting according to claim 9, wherein said groove is deeper than thecombined thickness of said disk and clamping ring, and said tabs areformed from material of said mounting ring malleably upset therefrominto said locking engagement with the clamping ring.
 12. A mountingaccording to claim 9, wherein said clamping ring comprises a rigid ringmember, and a resilient pressure spring ring disposed between said rigidring member and the margin of said disk and compressed by the rigid ringmember toward and into engagement with the disk margin.
 13. A mountingaccording to claim 12, said pressure ring comprising a concave convexcross section resilient metal ring having a convex face engaging thedisk margin.
 14. Mounting of a target disk within the end of a storagetube which includes a window panel across said end and a metal signalframe ring permanently secured between said window and said tube end andhaving an inside diameter which is smaller than an inside wall diameterof the tube, comprising: a target disk; said frame ring having a grooveinset in its radially inner axially inwardly facing margin within whichthe margin of said disk is seated; compressible means thrusting againstsaid disk margin; a clamping ring fitting in said groove and pressingagainst said compressible means; and means comprising locking tabscarried by said frame ring and thrusting said clamping ring toward saiddisk margin in said groove to maintain the compressible means undercompression against the disk margin.
 15. A mounting according to claim14, wherein said resilient compressible means comprise a concave convexspring ring having a convex face in engagement with said disk margin.